%0 Journal Article
%K Thin films
%K Raman scattering
%K Phase transitions
%K Bismuth compounds
%K Single crystals
%K Antiferromagnetic materials
%K Antiferromagnetic phase transition
%K Phonon coupling
%A M.O Ramirez
%A M Krishnamurthi
%A S Denev
%A A Kumar
%A S.-Y Yang
%A Y.-H Chu
%A E Saiz
%A J Seidel
%A A.P Pyatakov
%A A Bush
%A D Viehland
%A J Orenstein
%A Ramamoorthy Ramesh
%A V Gopalan
%B Applied Physics Letters
%D 2008
%G eng
%R 10.1063/1.2829681
%T Two-phonon coupling to the antiferromagnetic phase transition in multiferroic BiFeO3
%V 92
%X A prominent band centered at ∼1000-1300 cm-1 and associated with resonant enhancement of two-phonon Raman scattering is reported in multiferroic BiFe O3 thin films and single crystals. A strong anomaly in this band occurs at the antiferromagnetic Neel temperature, TN ∼375 °C. This band is composed of three peaks, assigned to 2 A4, 2 E8, and 2 E9 Raman modes. While all three peaks were found to be sensitive to the antiferromagnetic phase transition, the 2 E8 mode, in particular, nearly disappears at TN on heating, indicating a strong spin-two-phonon coupling in BiFe O3. © 2008 American Institute of Physics.